It is such a pity that yet another man, President Erdogan, is dreaming of becoming an Ottoman Sultan and establishing an Islamic Caliphate!
Saudi Arabia is an Islamic Sultanate in itself, and the Saudi King is believed to be the Muslim Caliph. Taliban also considers itself to be an Islamic Sultanate.
Daesh/ISIS also promotes Abu Bakr al-Baghdadi as their Caliph.
So many Islamic States, and so many Caliphs! That is exactly what is known as mischief within Islam.